Bast fibres obtained from dicotyledonous plants such as jute, hemp, flax, ramie or kenaf, have a number of commercial applications. Bast fibres have traditionally been used by the textile industry to manufacture spun products such as carpet yarn, rope, geotextile, traditional hessian and burlap. However, increasingly bast fibres are being used by other industries for such things as the manufacture of non-woven mats and carpets, composite materials, and automobile interior panels. Cellulose-based industries are also recovering cellulose from bast for use in pulp and paper production.
Before bast fibres can be used, they must be first separated from the inner core of the fibre plant by some form of decortication process. Prior art decortication processes vary but generally employ automated machinery that subjects the fibre plant to mechanical stresses that physically rupture the bond between the inner core and the bast. The machine then separates the bast from the inner core. Another process commonly employed to separate bast from the inner core is that of “retting”, which is a process of submerging the plant stalks in water, and soaking them for a period of time to loosen the fibres from the other components of the stalk. Retting can also be done by letting the cut crop stand in the fields exposed to atmospheric moisture. Bacterial action attacks pectin and lignin, freeing the cellulose fibres. The stalks are then removed and washed and subjected to mechanical processing to remove the soft tissue and then dried. A process employing a combination of retting and decortication machinery may also be used to obtain bast fibres.
The textile industry requires relatively long strand lengths of bast fibres. Accordingly, use of bast fibres in the textile industry has resulted in the development of decortication processes and machines that produce a longer staple of fibre, being 50 millimeters or longer, often in excess of 150 millimeters. However, the non-textile industries such as the cellulose based industry and composite moulding industries do not require long strand lengths and in fact, often have to cut the bast fibres into shorter lengths prior to use.
The removal of the need for longer fibres has created the possibility for the development of alternative decortication processes employing equipment that produces bast fibre strands having shorter lengths.